Surface electronic structure of complex B-metal perovskites

We present photoemission results for two systems, SrSn1−xSbxO3 and its row 6 analogue, BaPb1−xBix03. The variation in electronic structure as a function of composition is explored, particularly in the region of the metal-to-nonmetal transitions. In the case of the Sr system, dramatic surface segregation of Sb is revealed. This is analogous to that observed in Sn1−xSbx02. Resonant photoemission at oxygen and metal thresholds is used to explore the character of the valence band and gap states in these materials.